1. Field of the Invention
The present invention relates to a semiconductor device and a manufacturing method thereof, and relates to a NAND type memory cell and a manufacturing method thereof, for example.
2. Related Art
In NAND memories, there is representatively used an insulation film formed by polysilazane (PSZ), HDP-CVD (High Density Plasma-Chemical Vapor Deposition) or BPSG (Boron-Phosphorous-doped Silicon Glass) as an interlayer dielectric film filling between adjacent gate electrodes. A specific dielectric constant of each of these interlayer dielectric films is relatively low. However, when miniaturization of the semiconductor integrated circuit is progressed and when a gate length becomes 30 nm to 20 nm, there occur (1) a disturbance (threshold variation) due to a parasitic capacitance between adjacent floating gate electrodes, and (2) a disturbance (error writing) of a control electrode of a certain memory cell, inverting a channel of an adjacent memory cell. These problems of disturbances become a malfunction of the memory device.